[Mesa-dev] [PATCH 1/8] vbo: Ignore PRIMITIVE_RESTART_FIXED_INDEX for glDrawArrays().

[Kenneth Graunke]

The derived _PrimitiveRestart enable flag combines the PrimitiveRestart
and PrimitiveRestartFixedIndex enable flags.  However, DrawArrays is not
supposed to do FixedIndex restart:

>From the OpenGL 4.3 Core specification, section 10.3.5 (page 302):
"If PRIMITIVE_RESTART_FIXED_INDEX is enabled, primitive restart is not
 performed for array elements transferred by any drawing command not
 taking a type parameter, including all of the *Draw* commands other
 than *DrawElements*."

The OpenGL ES 3.0 specification agrees by omission:
"When DrawElements, DrawElementsInstanced, or DrawRangeElements
 transfers a set of generic attribute array elements to the GL..."

Notably, DrawArrays is not included in the list of draw calls that
take PRIMITIVE_RESTART_FIXED_INDEX into consideration.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/vbo/vbo_exec_array.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
index cf766af..cadb203 100644
--- a/src/mesa/vbo/vbo_exec_array.c
+++ b/src/mesa/vbo/vbo_exec_array.c
@@ -577,10 +577,10 @@ vbo_draw_arrays(struct gl_context *ctx, GLenum mode, GLint start,
    prim[0].base_instance = baseInstance;
 
    /* Implement the primitive restart index */
-   if (ctx->Array._PrimitiveRestart && ctx->Array._RestartIndex < count) {
+   if (ctx->Array.PrimitiveRestart && ctx->Array.RestartIndex < count) {
       GLuint primCount = 0;
 
-      if (ctx->Array._RestartIndex == start) {
+      if (ctx->Array.RestartIndex == start) {
          /* special case: RestartIndex at beginning */
          if (count > 1) {
             prim[0].start = start + 1;
@@ -588,7 +588,7 @@ vbo_draw_arrays(struct gl_context *ctx, GLenum mode, GLint start,
             primCount = 1;
          }
       }
-      else if (ctx->Array._RestartIndex == start + count - 1) {
+      else if (ctx->Array.RestartIndex == start + count - 1) {
          /* special case: RestartIndex at end */
          if (count > 1) {
             prim[0].start = start;
@@ -599,10 +599,10 @@ vbo_draw_arrays(struct gl_context *ctx, GLenum mode, GLint start,
       else {
          /* general case: RestartIndex in middle, split into two prims */
          prim[0].start = start;
-         prim[0].count = ctx->Array._RestartIndex - start;
+         prim[0].count = ctx->Array.RestartIndex - start;
 
          prim[1] = prim[0];
-         prim[1].start = ctx->Array._RestartIndex + 1;
+         prim[1].start = ctx->Array.RestartIndex + 1;
          prim[1].count = count - prim[1].start;
 
          primCount = 2;
-- 
1.8.3